📃 December 2014 release notes

New in Firefox

The following features are now available in Firefox:

Array copyWithin(): The copyWithin() method of arrays and typed arrays shifts or copies items of an array to another index of the array without changing its length.
font-feature-settings: The font-feature-settings CSS property sets low-level OpenType feature tags for a font. When possible, use font-variant instead.
font-language-override: The font-language-override CSS property sets which language-specific glyphs are displayed.
font-synthesis: The font-synthesis CSS shorthand property disables all font synthesis except the given kinds. To disable a specific kind of font synthesis, instead use the longhand properties such as font-synthesis-style and font-synthesis-weight.
font-variant-alternates: The font-variant-alternates CSS property, along with the @font-feature-values at-rule, chooses when to use a font's alternate glyphs.
font-variant-caps: The font-variant-caps CSS property sets whether text should be displayed in small caps, petite caps, or with capital letters designed for titles.
font-variant-east-asian: The font-variant-east-asian CSS property controls glyph substitution and sizing in East Asian text.
font-variant-ligatures: The font-variant-ligatures CSS property sets how characters can be visually combined for readability or stylistic reasons.
font-variant-numeric: The font-variant-numeric CSS property sets how numeric characters are displayed. For example, you can align columns of numbers or use zeroes that have a slash.
font-variant-position: The font-variant-position CSS property sets whether to use alternate glyphs for subscript and superscript text.
String raw(): The String.raw() static method interpolates template literal substitutions, but ignores escape sequences. It is the tag function for template literals.
WeakSet: A WeakSet object stores unique values of any type without creating strong references to the values, such that membership in the set does not prevent garbage collection of the value.
Web Cryptography: The Web Cryptography API performs low-level cryptographic operations, such as encryption, decryption, and signature verification. Also known as the Web Crypto API.

New in Firefox for Android

The following features are now available in Firefox for Android:

Array copyWithin(): The copyWithin() method of arrays and typed arrays shifts or copies items of an array to another index of the array without changing its length.
font-feature-settings: The font-feature-settings CSS property sets low-level OpenType feature tags for a font. When possible, use font-variant instead.
font-language-override: The font-language-override CSS property sets which language-specific glyphs are displayed.
font-synthesis: The font-synthesis CSS shorthand property disables all font synthesis except the given kinds. To disable a specific kind of font synthesis, instead use the longhand properties such as font-synthesis-style and font-synthesis-weight.
font-variant-alternates: The font-variant-alternates CSS property, along with the @font-feature-values at-rule, chooses when to use a font's alternate glyphs.
font-variant-caps: The font-variant-caps CSS property sets whether text should be displayed in small caps, petite caps, or with capital letters designed for titles.
font-variant-east-asian: The font-variant-east-asian CSS property controls glyph substitution and sizing in East Asian text.
font-variant-ligatures: The font-variant-ligatures CSS property sets how characters can be visually combined for readability or stylistic reasons.
font-variant-numeric: The font-variant-numeric CSS property sets how numeric characters are displayed. For example, you can align columns of numbers or use zeroes that have a slash.
font-variant-position: The font-variant-position CSS property sets whether to use alternate glyphs for subscript and superscript text.
String raw(): The String.raw() static method interpolates template literal substitutions, but ignores escape sequences. It is the tag function for template literals.
WeakSet: A WeakSet object stores unique values of any type without creating strong references to the values, such that membership in the set does not prevent garbage collection of the value.
Web Cryptography: The Web Cryptography API performs low-level cryptographic operations, such as encryption, decryption, and signature verification. Also known as the Web Crypto API.